An object on the end of a spring with spring constant k moves in simple harmonic motion with amplitude A and frequency f. Which of the following is a possible expression for the kinetic energy of the object as a function of time t ?
a) kA²sin²(2ft)
b) kA²sin²(2ft)
c) kA²cos²(2ft)
d) 1 half kA²cos²(2ft)
e) kAsin(2ft)
f) 1 half kAsin(2ft)
g) kAcos(2ft)
h) kAcos(2ft)
i) kA (sin 2ft cos 2ft)